docs: def _get_centered_ztor(self, rup, Frv):
          """
          Get ztor centered on the M- dependent avarage ztor(km)
          by different fault types.
          """
          if Frv == 1:
  
              mean_ztor = max(2.704 - 1.226 * max(rup.mag - 5.849, 0.0), 0.) ** 2
              centered_ztor = rup.ztor - mean_ztor
          else:
  
              mean_ztor = max(2.673 - 1.136 * max(rup.mag - 4.970, 0.0), 0.) ** 2
              centered_ztor = rup.ztor - mean_ztor
  
          return centered_ztor